Aberration correction for retinal imaging by magnetic fluid deformable mirror with dual-layer actuators

Adaptive optics (AO) is widely used to correct aberrations in human eye to obtain high-resolution retinal images. The existing single wavefront corrector is difficult to correct both low-order and high-order human eye aberrations for all possible cases. To improve the universality of the AO imaging system, in this paper a magnetic fluid deformable mirror (MFDM) with dual-layer actuators is designed and implemented in the retinal imaging system for large aberration correction. The structure of the dual-layer MFDM is first designed, then a hybrid algorithm is proposed to control the designed MFDM. Experimental evaluation of the effectiveness of the designed dual-layer MFDM and the hybrid control algorithm is conducted in the retinal imaging system. The results show that the system can simultaneously correct both low-order and high-order aberrations during imaging and obtain high-quality images.